Pulse effects of terahertz radiation in molecular gas mediums

Propagation of a pulse THz radiation through molecular gas mediums has series of features. In the paper three of them (giant light speed reduction, commensurate echoes, and non-Faraday rotation of polarization) are presented. The effects were measured directly in real time by a powerful pulse radiation of the Novosibirsk terahertz free-electron laser and our ultrafast detection technique.